Lateral Translation of Explosion Crater Ejecta: A Working Model Based Upon Pellet Experiments.

摘要

The purpose of the present study is to empirically characterize the 'transformation function' by which the excavation phase of an explosive cratering event translates material from a pre-event position to a post-event range within the ejecta deposit. The relationship between the original and final position of ejected material places important constraints on the distribution of shock stress and kinetics energy produced within the test medium by the explosion. This, in turn, permits the association of observed ejecta morphologies such as the hummocky and grooved terrain observed within the continuous ejecta deposit, ejecta rays, and discontinuous ejecta clusters with the relative levels of energy distribution within the test medium. The explosion cratering experiments described in this report were designed to empirically describe the material translation process. Tracer pellets were emplaced at specific positions within the test medium prior to a shot, then these pellets were located and their final positions were surveyed after the shot. All experiments were conducted at SDOB in the range appropriate to the impact crater analogy. Thus, the results of the present study can be directly compared with small impact cratering experiments.